Steering issues - Multiple symptoms - one problem

This one was kind of fun ... in a terrifying sort of way. Thought I'd pass it along.

The car in question is a 1968 type-3. The front brakes are disks. Rears are drums and adjusted equally. I replaced the ball-joints, tie- rod ends and rear spring plate bushings a little over a year ago. They are still OK.

First the symptoms:

Car pulled to the left under braking. Goes straight otherwise.

The horn would occasionally sound when braking and turning right (like into my driveway) and at only one position of the steering wheel. No braking, no horn. Also, the steering column felt stiff under braking.

Tonight on the way home I figured out what would account for all these.

The steering box was just loose enough to rotate a little on the beam. I couldn't move it by hand, but under braking, the tie-rods push inward and, because of the angles involved, upward on the pitman arm. And the steering box was moving a little on the beam. The little safety tabs that are supposed to keep the bolts from loosening were in place. Go figure.

Because the left tie rod is at a more acute angle than the right, the change in tow is more pronounced at the left wheel and the car pulled to the left under braking.

The upward movement of the pitman arm allowed part of the steering coupler to make contact with the bottom of the fuel tank, sounding the horn. This also put tension on the bearing up in the steering column, making it feel stiff. This may also have damaged the turn-signal switch.

So tonight I emptied and removed the tank and got everything straightened out and tightened up the steering box bracket. Things feel much better now. I do need to recheck tow-in now since that would be impacted by the rotating steering box.

Max

Reply to
max_welton_2k
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Now, that was a new one! Good you caught it in time.

J.

Reply to
P.J.Berg

LOL! Good sleuthing.

Here's another possible cause of pulling to the left:

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:)

Reply to
Speedy Jim

p/volks/pics/pulls.gif

Ha! :D

That left arm must get more, uh, sunlight than the right. :P

Max

Reply to
max_welton_2k

Tonight I reset the toe.

And using a tape measure is kind of a pain working alone.

So I made a tool to help me measure that using two washers, a screw, some tape and a stick.

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The idea is to hook the washer in a tread groove on one tire and mark that same groove on the other tire. Do this on the front and back tread, then compare.

See the marks on the tape? I was toed-in a bit. It's much better now.

8)

Max

Reply to
max_welton_2k

great job Max! I have a "tool" I made years ago, after buying a set of turntables, so I could set the toe... it is similiar to yours in function, but uses the rim's edge instead of the tires tread... it consists of a square tube with a smaller square tube that fits inside the first... this makes it adjustable width-wise,.,, on the end I welded an offset pointer of sorts (it extends upward then outward so the tool can reach up to the center of the rim both front and rear where a straight line from side to side isn't possible). i clamped an 18" low profile level to the top of the adjustible part so it can be held level ( welded a nut onto the larger tube so a bolt could be screwed down to lock the width if needed)... works great... It's packed up and in storage and i really need to get it out to check the alignment on my ghia...

Reply to
Joey Tribiani

I fabricated an alignment tool also some time ago. It is a bit more "modern", so yours may work better and be easier to use. Mine might be more accurate, but takes a bit more measuring and mathematics. Not trying to sell my method but I will tell this for amusement and to point out the craziness of an engineer.

I used a cheap Biltema (Scandinavian cheap auto parts and tools shop chain) water level with a laser pointer. Hooked it up to a piece of wood and measured the error angle between the straight edge of the wood and the laser line. The piece of wood was there to protrude the laser out of the rim so that it is visible and to match the lenght of the straight edge to the rim size. The laser is quite small. This is the laser part, without the tripod:

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Then I park the car in the garage with steering wheel straight. Tape up pieces of paper (A4 size was ok) In the front and back walls of the garage on both sides so that when I put the laser+wood-tool to the wheel, the laser dot hits the paper. Mark a "center line" somewhere in all the papers vertically and measure the distance between center lines in the front and in the back. Also measured distance between all wheel centers to the front and back walls.

Then I put the laser "tool" on all the wheel rims so that the straight edge of the wood (and straight edge of the laser) is towards the rim. And measure the difference from the paper center line both in front and back. Then it is all up to Excel, trigonometry and I get out the amount of toe, and how much the front wheel center line is off the line that the back wheels go. With this info I get enough data how much to adjust the front wheel toe on each side. At least this works very accurately when the toe is supposed to be 0 (that is the case with my daily driver).

I can describe the setup and my own theory more, if someone is interested.

Reply to
Olli Lammi

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LOL.... Olli... i worked directly with my share of engineers over the years.... One of my friends(vw guy) is an engineer... You guys like to make everything complicated!!! LOL... When my friend was building his vw's engines he had lots of questions... once he got answers he had to overanalyze them until he was confused... then, and only then, he could look at it from all angles until he understood it completely... He knew he made it more complicated but also knew that the education and such associated with engineering had programmed his brain to only accept what he fully understood and could "prove"... interesting to watch how his mind worked even if i did want to just shake him like a ragdoll sometimes...

Go ahead and post more, it's always nice to see other options and understand your vw enthusiasts ideas...

Reply to
Joey Tribiani

Personally - I don't require the proof to believe something. At least if things seems somewhat logical. But easily if I try to figure out something myself, I have the ability to do so and it usually involves some getting to know the theory behind things.

Well it all started when my daily driver had a worn out tie rod end. The dealership quoted me something outrageous for changing the rod end and doing the required wheel alignments. So, because I am cheap and I don't want to spend too much money on my over 300000 kilometers driven car (Year 2001 Ford Mondeo Sportback), I decided to do the whole thing myself.

Replaced both the tie rod ends and moved to check the alignment. First I tried to measure the toe with a tape measure but it is very impossible to be able to easily measure anything with one man from that car. There is no obvious straight path for the measure under the car. I was not able to come up a good way to measure so I thought that when the dealership does a laser alignment, I will be all laser also ;) Alignment without lasers is for sissies...

As an engineer - as Joey seems to know - I first studied some theory and calculated the equations and required variables to measure the toe. Another driver to this more accurate thinking was also the fact that after installing the new tie rod ends, the steering wheel was not absolutely centered when driving straight. So I had to think also how to adjust the thing so that it fixes also that problem.

After thinking about it it was obvious that in order to get meaningful results, I need to be able to trust the laser setup so that the laser is really showing exactly as the wheel is aligned. As I am cheap, I had only budget for this cheap laser and in addition I had to extend it with a piece of wood. I tried to calibrate it, but it was still more or less like guesswork.

This is what the "tool" looks like:

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So engineer in me decided to measure the error in the angle of my tool. To do that I used a portable work bench with something straight attached to it. To be able to measure the error, I had to had something that I trust enough to be straight. So I used my water level (or what is the correct name for the straight metallic tool with the water levels). I taped a sheet of millimeter paper to the wall and measured the distance of the laser dots with the paper between different sides of the water level. Measured the distance between the paper and the tool center. Then I moved the work bench farther away and repeated the measurements, again farther away and repeated. The values (tool center distance from the paper and distance between laser dots on the paper from different sides of the straight object) give me then an approximation of the tool angle error.

The math equations and trigonometry then contained the error angle also. I did some assumptions in the math because it seemed like given the used measurement accuracy, they would not be affecting the results.

The actual measurement of the wheel alignment needs to be done either at two different distances from one wall or using two walls (front and back). I used the 2 wall method. Basically the idea is that we choose one vertical line from both walls and measure the laser point distance from that line when the tool is inserted on each wheel. Also distances from center of each wheel to both walls are measured.

The distance between points in the front wall and distance between points in the back wall will then give basis to calculate the wheel angle if we also have the wheel distances from the walls and the tool angle error value. There would not be any need to measure the back wheels, but as I wanted to straighten the wheel and I thought that the rear wheels are the ones that set up the "straight" when considering where the car is pointing, I measure the rear wheel given center point of the car as half way of the laser points on each wall.

From the combined alignment of the front wheels and the location of the front wheel points on the wall regarding the center line - I can calculate how much I needed to adjust each wheel to make the front wheel center the same as the rear wheel center. All of the measurements were of course made when the steering wheel was turned straight.

Measuring the tie rod end distance from the wheel hub center and the thread pitch in the tie rod, I could calculate the amount to turn in or out the tie rod on each side.

... and of course there is an Excel for all this ...

To help to carry out the measurements on the walls, I taped again millimeter paper to the wall where the laser point hits and marked a 0-line on both of the papers. Then I measured the distance between the paper 0-lines. After that I could then read the laser point locations on the papers proportional to the 0-lines (for example +35mm). Reading the laser on the paper while holding the tool was ok.

After all this, checking after the adjustment and test drives - I think I managed actually to correctly adjust the toe. The steering wheel also was straightened. I am also sure that with some carpenter skills and tools one could easily make a tool that could be used to measure the toe without fancy lasers and mathematics. I had no place or tools to do that at that time.

Equations - that is another story then about this overkill alignment.

Reply to
Olli Lammi

Olli, I am prepared to believe you spent more time typing that post than I spent making my "tool".

:D

Max

Reply to
max_welton_2k

People do crazy things - mee too ;)

Reply to
Olli Lammi

in the end, being satisfied that you got the job done is what really matters.... I can think of ten different and easier ways to get it within tolerances, but wow..... you basically duplicated the computer alignment racks, you being the computer!! great job!

Reply to
Joey Tribiani

I like it! I also have two of those laser levels to do wheel alignments. ;-) I too believe in using lasers like the pros do so I am still listening to all ideas!

Reply to
dave AKA vwdoc1

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